An incredibly heavy but extremely effective suit of crystalline armour.

Crystal plate armour is the heaviest non-dragon armour available, and requires high strength to wear effectively. It is also unusable by Spriggans, Ogres, and Trolls due to size restrictions and Draconians, Octopodes and Felids as they cannot wear any body armor. In exchange for these steep requirements, it offers phenomenal AC and GDR (48%!), allowing characters to absorb physical abuse with ease. Just don't expect to dodge many attacks or cast easily while wearing it.

Crystal plate armour is extremely rare, but it is generally considered to be very strong if your character has the strength to use it and doesn't mind or can counteract the high penalties.